Prefabricated stair



April 22, 1952 G. w. I YoNs PREF'ABRICATED STAIR Filed July 20, 1949 Il-l Z3 gli /n uen for @We /WMM Patented Apr. 22, 1952 UNITED STATES PTENT OFFICE 2,593,683 PREFABRICATED STAIR George W. Lyons, North Guilford, Conn. Application `uly 20, 1949, Serial No. 105,714 v 3 claims. (c1. 18e-43) The, present invention relates in general to staircases and more especially to a-flight of stairs adjustable vertically for meeting the requirements of a given installation.

'An object of the invention is to provide a superior prefabricated flight of stairs of durable, economical and relatively-simple construction.

A further object of the invention is to provide a superior flight of stairs embodying sectionalstringers formed of prefabricated tread-supporting' plates adjustable vertically with respect to each other for adapting the iiight of stairsto a given installation.

With the above` and other objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are novel over the prior art. 1 f

In the accompanying drawings, in which certain modes of carrying out the'present invention are shown for illustrative purposes:

Fig. 1 is a perspective view of a flight of stairs formed of the prefabrlcated tread-supporting plates of this invention:

Fig. 2 is a broken side elevation in section of a portion of a flight of stairs formed of the prefabricated tread-supporting plates of this invention, the vertical adjustment of the treadsupporting plates with respect to each other being indicated by broken lines;

Fig. 3 is a plan view in section on line 3-3 of Fig. 2 showing the fastening-means for securing the adjacent tread-supporting plates of the sectional-stringers together and for adjustment vertically with respect to each other;

Fig. 4 is a fragmentary front elevation in section on line 4-4 of Fig. 2 showing fastening- -means for securing one edge of the tread to the corresponding tread-supporting plate; and

Fig. 5 is a perspective View of one of the improved prefabricated flanged tread-supporting plates 0f this invention.

Referring to Fig. 1, the superior flight of stairs of this invention comprises a pair of sectionalstringers, indicated-generally at II and I2 respectively, each stringer comprising a plurality of adjoining prefabricated tread-supporting plates I3 and I3 respectively and treads I4 joining corresponding pairs of tread-supporting plates; the treads I4 being provided with integral toe-guards I5, each of which extends longitudinally of and is bent upwardly at substantially right. angles to the rear of its respective tread. The forward edge of each tread is rolled under to provide a rounded front ange I1.

Referring to Fig. 5, the latter shows a prefabricated tread-supporting plate I3 adapted, in'particular, for use in forming the left-hand sectional-Stringer II of the ight of stairs shown ln Fig. l, the tread-supporting plates I3' for the sectional-Stringer I2 of the flight of stairs being substantially identical to those of the sectional- Stringer II, except for such obvious reversal of parts as may be necessary to adapt the treadsupporting plates for use on the right-hand side of the flight of stairs. The tread-supporting plates of the sectional-Stringer I2 have, therefore, similar reference characters applied thereto, plus a prime Each prefabricated tread-supporting plate lI3 of the sectional-Stringer. II comprises a substantially-rigid channel-shaped member formed of relatively-heavy-gauge sheet 'metal and embodying a polygonal body-portion I8 having two straight rectangular substantially-parallel '1ongitudinal flanges I9 and 2l) respectively bentlup substantially perpendicular to the plane 'of the body-portion I8;A a straight substantially-reef tangular top flange 2| at substantially right angles to the corresponding anges I9 and 20 and bent up substantially perpendicular to the plane of the vbody-portion I8, the top flange 2| being on the same side thereof as the flanges I9 and 20; and a straight bottom edge 22. The latter may be at right angles to the respective side anges of the tread-supporting plate, but is preferably struck off at an angle with respect to the top flange 2I of the tread-supporting plate, as shown especially Well in Fig. `5. Although it is not essential to the successful use of the tread-supporting plate, the ends of the top flange 2| may be secured to the corresponding ends of the side flanges by welded joints or equivalent fasteningmeans.

A pair of laterally-spaced apertures 23 are provided in the top flange of the tread-supporting plate for accommodating fastening-means such as, for example, a bolt-and-nut assembly indicated generally. at 24 in Fig. 4, by whichl the corresponding end of a stair-tread I4 may be se'- cured to the top flange of the tread-supporting plate. The flange 20 along the'back edge of the tread-supporting plate is provided with three longitudinally-spaced apertures 25, each of which is adapted to accommodate fastening-means such as, for example, a bolt-and-nut assembly 26, for securing the back flange 20 of the tread-supporting plate to the front flange I9 of the next-succeeding tread-supporting plate immediately to the rear thereof, in the manner hereinafter described.

In this connection, the flange I9 on the front edge of each tread-supporting plate is provided with a plurality of sets of apertures 21, 28 and 29 respectively, the upper set 21 being made up preferably of six apertures and the two lower sets 28 and 29 respectively being made up of three aperturesf each. Although the vspecified number of apertures for 'the sets of apertures 2l, 28 and 29 has been found satisfactory for the purposes prescribed below, it will be appreciated that it is within the purview of the invention to provide more or less apertures per set. These respective sets of apertures constitute adlustingfmeansby which the individual tread-supporting plates of the sectional-stringers of the iiightiof-stairs may be adjusted vertically with respect to each other, as indicated by the broken lines in Fig. 2, and for the ,purpose described below.

,"In'the. preferredconstruction, the over-Qall adjustment of one tread-supporting lplate with respect yto"the.other, Vobtained by means of the aforesaid :sets of.adjusting'apertures in the front lflanges, I9 Of'thetrea'd-supporting plates, is substantially one Yand one-quarter inches and, consequently, assuming, for example, seven treadsupporting plates vareV used in avfiight of stairs, the'range of 'adjustmentvertically ofthe flight .of `st'airs'will 'fbeeight and three-'quarters inches. "Consequently, `ajgiven flight of stairsv maybe adj'jus'ted to vhave substantially uniformly high tread=supportlng platesl between successive steps in stair-openings which vary in height by as much. as eight and three-quarters inches. "To"f0rm aflight of stairssuch 4as Ashown vin Figs..i1 'and"'2,"ajprescr'ibed number of prefabricated leftand lrightside flanged tread-supportingplates, includingithe proper number of treads, are taken 'from stock :and assembledzas'follows. "Therearflangepf the Vforemost tread-supporting 'plate 'of the vflight `of stairs and Ythe front ange `Ilof 'the tread-,supporting plate immevdiately;l to the rear thereof are brought together, as ,shown `'especiaLllywell in Fig. 3, and Vrigidlysecured v:by means `of the'boltand-nut*assemblies 26. The latter engage in'the'three apertures 2e of the .flange .20 `and in corresponding axiallylaligned .apertures of'the three-sets of apertures '21,"28, and 29 in the front flange I9. It will be clearthat by engaging the'fastening-means 26 in'the'lowermost apertures of thethree sets of aperturesin the'flange I,9,'the foremost treadsupporting vplate will be secured to the next-succeeding'treadesupporting vplate immediately rearwardly thereof in its lowermost'positionvertically relative thereto, andthatby lengaging the'fastening-'means in successively higherapertures of the three sets of apertures in the front flange I9, thevvertical distance between the top flanges of the :respective `tread-supporting plates will be progressively lessened, 'thatis to say, the vtwo tread-supporting plates `may be adjusted vertically with respect .to,eachother so as to vary the height :of Nthe rise betweensuccessive steps, as indicated Aby the broken lines in Fig. 2. .By joining a plurality of tread-supporting-plates in the manner :described above, one mayquickly fabricate'two`-sectionalstringers of a flight of stairs rsuch as, -for example, the sectional-stringers II and :I2-respectively, ofsubstantially any length. .A tread I4 is then secured to the top flanges of ,the corresponding 4pairs ,of tread-supporting plates .of the sectional-.stringere I I and I2by means of the bolt-and-nut assemblies 24. 'Moreover, in order to make the' connection between successive tread-supporting plates more rigid, the toe-guard I5 of each tread is provided with apertures adjacent the outer ends thereof respectively, adapted to lie substantially opposite the front flanges I9 of the corresponding pair of tread-supporting plates immediately rearwardly thereof, and more especially to be in axial alignment with corresponding apertures of the upper sets ofapertures .21 therein, wherebyzfasteningmeans comprising bolt-and-nut assemblies 3G may be engaged therein, thereby connecting the tread of one tread-supporting plate with the Lfrontfanges of the tread-supporting plates immediately rearwardly thereof.

'It will be'appreciated that by securing to- `gether,aipredetermined number of prefabricated channeled tread-supporting plates in the manner hereinabove described, .a flight of stairs maybe constructed to t the stair-openings which vary widely in height, andlwithout the use `of stringers or other conventional framingmemberS, the flight "of `stairs'being relatively-simple Yto fabricate, inexpensive andof durable'con'struction.

Although the flanged'.treadesupporting plates and -treads aredesigned in particularfor use as components of fafiightofstairs, 'it will.. be :tappreciated 'that it is within' the `:purview of .the invention :to employ 'the .treadssupporting .plates and treads asfshowniand described herein,"or;.ob-

"vious "modicationszthereof, in tiother :capacities such as, for example, components 4of-fadisplaaty stand, shelf, table and the like.

The invention :may i be .carried foutin'other speelde-Ways thanthosehereinset forth without departing 'fromnthesspirit and. essential charac- -teristics -of 'the invention, ,andithe present :fembodiments are, therefore, to beiconsidered'inzall respects. as illustrative. and not :restrictiva and all Nchanges .coming .within "the meaning and equivalency range of the.appendedzclaimsfare .in-

tended'to be .embraced therein.

Ybeing constructed l`of a plurality of similar flanged tread-supporting plates, -saidplates each having a tread-supporting ange along its 4upper edge and parallel side iiangesalong its side edges; fastening-means securing the abutting side anges of successive tread-supporting plates substantially rigidly together; `and treads secured to the tread-supporting anges 'of the `correspending pairs of tread-supporting plates of vsaid two Ksectional stringersgeach of said treads'having an integral toe-guard fastened to the flanges of `the next-succeeding pairs of tread-supporting plates.

3. Aprefabricated flightV of stairs comprising 'two sectionalstringers, each stringer being constructed of 4aplura'lity of similar rflanged 'treadsupporting plates, said plates .each having `a tread-supporting flange along 'itsupper "edges and parallel side ilanges along its side edges; adjusting-means 'n' the side anges of said-treadsupporting plates; fastening-means in engagement with the adjusting-means of the abutting side iianges of, successive tread-supporting plates and securing the latter substantially rigidly togather in vertically-adjusted position with respect to each other; treads on the tread-supporting flanges offthe corresponding pairs of treadsupportng pl tes'of said two sectional stringers; w

' -Number and fasteningfineans securing said treads to the tread-supportingilanges of the corresponding pairs of tread-supporting plates and to the corresponding side anges of the next-succeeding pair of tread-supporting plates of said two sectional stringers.

` GEORGE W. LYONS.

REFERENCES CITED The following references are of record in the file of thispatent:

UNITED STATES PATENTS Name Date 1,002,096 Todd Aug. 29, 1911 1,708,394 Mugler Apr. 9, 1929 

